Lipolysis of very low density lipoproteins by heparan sulfate proteoglycan-bound lipoprotein lipase.
An in vitro assay to study lipolysis of very low density lipoproteins (VLDL) by heparan sulfate proteoglycan (HSPG-bound lipoprotein lipase (LPL) was developed. Optimal conditions for VLDL lipolysis by HSPG-bound LPL were obtained by incubating plastic wells with 0.5 microg HSPG and 1.5 microg LPL, subsequently. Control experiments with heparinase indicate that at least 90% of the LPL activity is derived from LPL bound to heparan sulfate chains. For HSPG-LPL-mediated lipolysis, the apparent Km and Vmax values were 0.36 +/- 0.11 mM VLDL-triglycerides and 1.2 +/- 0.1 microM free fatty acids/min x ng LPL, respectively. The mean intra-assay and inter-assay coefficients of variance were 5% and 8%, respectively.
de Man
F H
FH
Department of Cardiology, Leiden University Medical Centre, The Netherlands.
de Beer
F
F
van der Laarse
A
A
Smelt
A H
AH
Havekes
L M
LM
D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D005227:Fatty Acids / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism*; D019763:Heparin Lyase / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D007700:Kinetics; D008066:Lipolysis; D008071:Lipoprotein Lipase / Q000378:metabolism*; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D011485:Protein Binding; D011869:Radioligand Assay; D014280:Triglycerides / Q000378:metabolism
D005227:Fatty Acids; D019812:Heparan Sulfate Proteoglycans; D007457:Iodine Radioisotopes; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D008071:Lipoprotein Lipase; D019763:Heparin Lyase